Adhesive capsulitis or “frozen shoulder” is a clinical condition characterized by pain and stiffness of the shoulder joint (the patient has difficulty moving the arm, as if it were “frozen”).Even 150 years after its first description, its meaning as a disease remains uncertain and its etiology controversial.
Clinically, rigidity is sometimes common to other diagnoses and may suggest, for example, arthrosis, but the characteristics of the pain associated with it are usually quite different from those that characterize capsulitis.Adhesive capsulitis affects 2 to 5% of the general population, mainly between the 4th and 6th decade of life and with a particular incidence on the non-dominant shoulder.
In other words, if the person is right-handed, it affects the left shoulder more frequently, whereas, if the person is left-handed, the right shoulder is more affected. Bilateral involvement is rare, although it is possible to reach both shoulders in a phased manner, with an interval generally less than 5 years.
There are three phases of adhesive capsulite or “frozenshoulder”:
- Acute initial phase, “freezingphase” – is characterized by the insidious onset of diffuse pain and limited range of motion (active and passive) of the glenohumeral joint. It lasts for about 2 to 9 months.
- Second phase, “frozenphase” – in the next 4 to 12 months, the pain progressively decreases, but movement limitation remains, with an almost total loss of external rotation.
- Resolution phase, “thawingphase” – occurs spontaneously, with gradual improvement in range of motion and pain resolution. It has an average duration of 2 to 3 years.
Adhesive capsulitis is usually idiopathic, so by definition it has no known cause. There are, however, some situations in which the causal factor is identified and then capsulitis is called secondary. Among the most frequent known causes of adhesive or retractable capsulitis are trauma, with or without associated fracture, surgery or systemic causes such as diabetes or thyroid disease.
Normally, what occurs in the chronic inflammatory situation is a progressive capsular fibrosis due to an increase in the deposition of inflammatory chemical mediators (called cytokines), with the consequent retractile capsulitis.
Adhesive capsulitis – risk factors
As mentioned, diabetes is one of the pathologies most often associated with adhesive capsulitis, being present in 20% of the cases in which it occurs.
Adhesive Capsulitis – Symptoms
The clinical picture is characterized by diffuse pain throughout the shoulder, with an insidious onset and evolution over a few weeks. There is usually nocturnal aggravation and can also lead to a limitation in the active and passive range of motion of the joint, which ultimately leads to a complete blockage of mobility.
The aggravation of these symptoms can cause a great limitation and even interfere with activities of daily living, making it extremely disabling for professional activity as well.